Bath tub



FIG. 1 is a top, front, left side perspective view of a bath tub showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a right side elevational view thereof;

FIG. 4 is a left hand side elevational view thereof;

FIG. 5 is a front elevational view thereof, the rear being identical;

FIG. 6 is a bottom plan view thereof. 

The ornamental design for a bath tub, as shown and described. 